U.S. Pat. No. 3,730,475 (Werfel) issued May 1, 1973 discloses a form for use in casting a foundation or footing where there are two side walls converging upwardly and inwardly to an open top where the side walls are bridged by pair of straps with top portions which can be used as handles. The forms are arranged in a row to define the footing and cab be lifted off after the concrete is poured and set.
The forms are not however convenient to use and to adjust to the required position.